Airplanes or helicopters include thin structural elements of sizes that can be quite large, and that need to withstand various mechanical stresses that may act in various directions, while remaining as lightweight as possible.
It is known to make such thin structural elements from plates made of fibers such as carbon fibers, glass fibers, or aramid fibers. Within the plates, the fibers are assembled together in layers or plies that are assembled to one another, in particular by weaving. The plates thus possess a certain amount of strength that enables them to be cut and handled. Portions cut out from such plates are then assembled together, after which they are impregnated with a polymerizable resin in order to obtain the structural element.
One well-known means for conferring stiffness to thin structural elements while minimizing the weight of said thin elements consists in applying stiffeners thereto.
The prior art is illustrated in particular by the following documents: U.S. Pat. No. 462,254, EP 1 023 986, EP 0 056 352, U.S. Pat. No. 5,518,564, and U.S. Pat. No. 4,966,802.